After a deep dive on rendering unicode pixel fonts in a web browser, I concluded: (a) there are no good, open unicode pixel fonts except the GPL2 X11 ones, and (b) browser TTF rendering is such an unstandardized mess that there's no point...use manual bitmap fonts if you care about pixels.
Paeth rotation is the algorithm for implementing sprite rotation using three shears. It was a popular demo scene trick and is still used by ImageMagick.
I'm rotating some tiny sprites under a low-color palette with nearest neighbor rotation, and they look horrible of course. I wondered, will Paeth rotation look better? The answer is, no, it gives exactly the same result as nearest neighbor--the advantage was integer perf, not quality.